Webmaster showing lot of 404 error pages, .aspx in the end

Hell friends this is Sumit chauhan again. My fist form is related to Drop in ranking . and we had a long discussion on that . you can check it here. Today i am facing some 404 error page problem with the same website. Webmaster is showing a lot of 404 url's taving .aspx in last like :- "Logistics_faq.aspx " , please tell me how to remove it and why webmaster is showing these type of url in repost .